In order to detect foreign matter in a cylindrical container, for example minute foreign matter in an injection agent liquid in an ampoule, vial, syringe, and the like, a foreign matter inspection device is used. In detecting minute foreign matter, in the foreign matter inspection device, a whirling liquid stream is generated in liquid in a container around a vertical cylindrical container axis by spinning and the like, the minute foreign matter floating and moving in the liquid is photographed, picture difference data are analyzed, and the foreign matter is detected.
In Patent Literature 1, it is described that, in a foreign matter inspection device including an infrared irradiation device and an infrared imaging device picking up a fluoroscopic image of a container and an extracting means photographing movement of foreign matter at a predetermined temporal interval and extracting foreign matter images from the image data and, in rotating the container, adjusting the center axis of a container to a constant angle relative to the horizontal direction, the moving distance of the foreign matter is determined by acquiring information at every constant temporal unit, and a substance with heavy specific weight and settling quickly and a substance with specific weight close to that of the liquid and continuing a floating state are differentiated.
In Patent Literature 2, a foreign matter inspection device is described in which a container is rotated in a state a small diameter part of a container is supported in a generally horizontal manner, liquid in the small diameter part is temporarily moved to the container body side by a centrifugal force, rotation is thereafter stopped, and movement of foreign matter inside the container is detected by image processing.